Fire alarm



A. YOHN 2,428,107

Sept 30, 1947.

\ FIRE ALARM Filed A a- 1946 HLB 'K' H N MZU Patented Sept. 30, 1947 UNITED STATES I PATENT OFFICE Albert Yohn, Bufialo, N. Y. Application August 20, 1946, Serial No. 691,842 i Claim. (01. 116-106) This invention relates to improvements in fire alarms.

An object of the invention is to provide an improved audible fire alarm.

Another object of the invention is to provide an improved audible fire alarm in which a spring projected firing pin will be held in tensioned position by means of a bell crank lever trigger memher and a suitable fusible link in position to fire a blank cartridge when said link is melted due to the heat from a nearby fire. I

Another object of the invention is to provide an improved audible fire alarm signal which will include a slidable firing pin and an aligned blank cartridge holder, said firing pin being held in retracted position by means of a coil spring under tension, the same being held by a bell crank shaped trigger lever having a latch formed at its inner end and a fusible link secured between the same and a fixed support upon the fire alarm housing.

A further object of the invention is to provide an improved audible fire alarm consisting of a body member being formed with a plurality of spaced apertures serving as a sounding board, together with a blank cartridge holder and a spring projected firing pin held in cocked position by means of a strand of fusible metal wire, whereby when a fire gets too close to the fire alarm signal, the fusible link will melt, thereby releasing the spring tensioned firing pin which will be projected forwardly to engage the head of the blank cartridge to explode the same, giving a, warning to persons in adjacent places that a. fire is burning close by.

Another object of the invention is to provide an improved fire alarm signal formed with a cartridge holding box and a, spring retracted firing pin adapted to engage the blank cartridge, and a perforated cover or sounding wall therefor.

Another object of the invention is to provide an improved audible fire alarm signal which will be highly efficient in operation, andrelatively inexpensive to manufacture and produce.

Other objects will appear as the description proceeds.

In the accompanying drawings which form a part of this application, 1

Figure 1 is a front elevation cover for the fire alarm signal;

Figure 2 is an edge view of the fire alarm signal;

Figure 3 is a front elevation of the fire alarm signal with cover removed;

of the perforated panying drawings to designate corresponding ing a base plate I preferably formed of metal and having an upstanding ear 2 along its central upper edge, said ear being perforated at 3 for supporting the signal upon a nail or hook (not shown).

A cartridge supporting block 5 is suitably mounted on the base plate I, and is formed with a bore 6 in which a blank cartridge 1 may be inserted. An upstanding inwardly directed guard 8 will be disposed on the plate I slightly spaced in front of the block 5, to protect persons from injury or powder burns when the blank cartridge is fired.

Disposed upon the base plate I adjacent the block 5, is a guide block 9 through which the metal firing pin lll is slidably mounted. The front end ll of the firing pin I0 is bevelled off to provide a. more-or-less pointed end for engagement with the firing cap in the face of the cartridge.

The adjacent side edge of the base plate I is rolled as/at l2 to provide a cylindrical housing in which the head 13 On the rear end of the firing pin I0 is freely slidable, engaging one end of a coil spring I 4, also mounted in the housing l2, the opposite end of the spring engaging the disc head 15 which is supported in place in said housing by the inwardly directed fingers l6 formed thereon.

A longitudinally extending slot I1 is formed between the lower end of the rolled housing l2 and said base plate I, and is provided to receive the hooked end or trigger end [8 of the bell crank I to anchor the looped end of the fusible metal link 22, whose opposite end is looped over the ad- 7 jacentend ofthe trigger bar I 9 to hold said firing pin l0 cocked against the tension of the said coil spring l4;

I, A perforated cover 23 for the fire alarm signal is provided, the perforations 24 being provided to permit the ready egress of the sound to pass out of said fire alarm signal when the blank cartridge i is fired. The cover 23 is further apertured at 25,

through its edge to permit heat to reach the fusible link 22 to operate the fire alarm signal should the heat rise above a predetermined point. The

cover 23 further acts as a sounding board to increase and multiply the volume of sound emitted when the fire alarm signal is actuated.

Fromthe foregoing description, it will be seen that since all parts of the fire alarm signal are formed of metal, the fusible link 22 will be readily melted when the temperature of a room equipped with the improved fire alarm signal is increased sufliciently due to the presence of a nearby fire, thereby releasing the trigger bar I9, which in turn'releases the spring tensioned firing pin to fire the blank cartridge.

Due to the construction of the fire alarm signal and the low cost of blank cartridges, the device may be installed and used over a long period of time with a minimum original expense and maintenance cost.

While the preferred embodiment of the instant invention has been illustrated and described, it will be understood that it is not intended to limit the scope of the invention thereto, as many minor changes in detail of construction may be resorted to without departure from the spirit of the inven- Having thus described my invention what I claim as new and I desire to secure by Letters Patent of the United States is:

An audible'fire alarm signal including a fiat base plate having a portionof one edge thereof rolled to form a tubular housing open'at one end and formed with inwardly directed spring-supporting fingers on its opposite end, a coil spring seated on said fingers, a firing pin block on said base adjacent said housing, a headed firing pin slidably supported in said block with its headengageable with the adjacent opposite end of said coil spring, a cartridge block aligned with said firing pin block and coil spring housing disposed upon said flat base, a blank cartridge in said cartridge block, the adjacent end of said flat base being bent upwardly and inwardly adjacent said cartridge block to provide a powder guard, a bell crank lever trigger pivotally supported on said fiat base engageable with said firing pin head to compress said firing pin projecting spring when said trigger is in set position, an anchoringpin on said fiat base, a fusible link supported by-sald bell crank trigger engageable with said pin for holding said firing pin in cocked position, and a perforated cover removably supported upon said flat base forming a sounding board and having an aperture extending through one edge thereof adjacent said fusible link for permitting heat to enter directly through said cover to melt said fusible link in case of fire.

ALBERT YOHN.

' REFERENCES CITED The following references are of record in the 'file of this patent:

UNITED STATES PATENTS Number Name a Date 718,211 Lombard Jan. 13, 1903 1,229,299 Lindemann June 12, 1917 2,013,466 Jones Sept. 3, 1935 2,015,984 Wood Oct. 1, 1935 2,270,226 Pease Jan. 13, 1942 

